بررسی ارزش رجحانی گونه های مرتعی و رفتار چرایی دام در مراتع نمونه پنج منطقه رویشی ایران (مازندران-پلور)

phenology and vegetative characteristics which have certain grazing value. Withought distiguish this behaviours not possible range management.We have studied the daily distance traveled, speed trap, the time spent for travel and rest with sing GPS.Preference value of rangeland plant species was determined with two method timing and precent of using.Time of the year 2007-2010 has been investigated.The results show that livestock grazing behavior is different in different months of the season grazing. On average, over the livestock grazing season distance of 14.84 km n the first month, second month in a distance of 13.30 km and 12.38 km distance of the third month. Preference value of the plant species shows that species such as Elymus hispidus, Bromus tomentellus, Festuca ovina, Taraxacum montanum, Tragopogon graminifolius and Arenaria gypsophiloides have more time devoted to the preference index. Plant Species such as Dianthus orientalis, Thymus pubescens, Geobelia alopecuroides, Papaver bracteatum have less time devoted to the preference index. Density and percent cover of the species has an important role in the preference value of rangeland species. The results show that the timing and forage precent using methods for assessment of preference value are relatively equal in present value of the preference ranking. Maximum speed and movement of livestock is in the first month and the lowest speed and movement of livestock is the second grazing season. Most animal movement (km)is on slopes 0-15 percent and its lowest in more than 60 percent slopes. Most animal movement (minutes) is on slopes of 30-15 percent and its lowest in more than 60 percent slopes. Key words:Timing,Preference index,Grazing behavior ,Using percent